Conventionally, pilots use weather radar systems to detect and avoid hazardous weather. Weather radar systems typically include a radar antenna which transmits radar signals and receives radar returns. The radar returns are processed to provide graphical images to a radar display. The radar display is typically a color display providing graphical images in color to represent the severity of weather. Conventional weather radar systems includes those manufactured by Rockwell Collins, Inc. and Honeywell International, Inc. and others.
Most conventional weather radar displays require a vast amount of digital storage capability. For example, raw quadrature data (I, Q data) digitized from radar returns can require approximately 4.9 megabytes for each four second scan. According to an ARINC 453 standard, the raw quadrature data is processed into a smaller data stream that is used to provide graphical images on weather display. The data stream of the ARINC 453 standard requires approximately 140,000 bytes to store each 4 second scan. Accordingly, the vast quantity of data associated with radar scans makes real time, data storage during flights difficult. This difficulty may be enhanced as radar techniques became more sophisticated and process even more data.
Further, the large amount of data associated with weather radar systems makes long-term storage of such data and/or downlink transmissions of such data nearly impossible. As a result, post-flight evaluation of radar performance must often be conducted based upon pilot memory and conjecture rather than recorded weather radar data. For example, if an aircraft experiences a weather pattern which is not indicated on the display, the pilot must mentally remember what was on the display at the time of the weather pattern.
Conventional weather radar systems do not include a mechanism for storing the weather radar data or even the graphical images provided to the pilot on the display. Having weather data for post flight analysis would be helpful in assessing any unusual weather encounters experienced by the flight crew. In addition, this data could be transmitted to ground based personnel for dissemination to other aircraft or could be transmitted directly to other aircraft. According to another example, if an aircraft experiences lightning, a wind shear event, a sudden gain or drop in altitude due to weather or other event, it would be desirous to store data associated with the weather radar display at the time of the event.
Thus, there is a need to provide a system and/or method that allows weather radar data to be stored in response to an event. Further still, there is a need for a system and/or method that compresses data to a more manageable size. Yet further, there is a need to store data or download data that reflects the graphical images provided to a pilot on a weather radar display. Even further still, there is a need for a system and/or a method that reduces the amount of data required to provide an approximation of the graphical images on a weather radar display. The teachings disclose the extent to those embodiments which fall within the scope of the appended claims regardless of whether they accomplish one or more of the aforementioned needs.